1. Field of the Invention
The present invention relates to a light source for a laser microscope, a biomedical analyzer, a precision measurement device, and the like.
2. Description of the Related Art
Conventionally, a light source used for, for example, a laser microscope, a fluorescence analyzer for biomedicine, a biological analyzer for biomedicine, and a precision measurement device, includes a semiconductor laser or a light source that generates a harmonic light by pumping an SHG (second harmonic generation) element or a THG (third harmonic generation) element that serves as a harmonic generating element such as a nonlinear optical crystal with a semiconductor laser. A light generated by the semiconductor laser has a specific wavelength, and a harmonic light generated by the SHG element or the THG element has a wavelength of a half or a third of a wavelength of a semiconductor laser used for pumping.
An optical fiber laser employing an optical fiber is disclosed as a light source that generates a light having a desired wavelength (see, for example, Patent Document 1:Japanese Patent Application Laid-open No. 2005-12008).
In an apparatus such as a laser microscope, for example, a light having a wavelength between 530 nanometers and 600 nanometers is necessary to perform fluorescence analysis of protein. To generate a light having a wavelength within such a wavelength band with the SHG element, a light source that generates a light having a wavelength between 1060 nanometers and 1200 nanometers is necessary.
However, a conventional light source has a problem that a light output is not stable enough. Particularly, a light source used in combination with a harmonic generating element results in a problem that an output of a harmonic light generated by the harmonic generating element is unstable.